Other way around. The Guardian speculated in 2013 http://www.theguardian.com/business/economics-blog/2013/jun/... that if Britain had joined the Euro:

* The mid-2000s British housing bubble, and its collapse in 2007, would have been even bigger.

* Britain would have had to ask the IMF, ECB, and EU for loans.

* The Tories would in 2010 have promised a referendum to leave the Euro and won a majority. Labour would have won fewer than 100 seats, and UKIP would have "made spectacular gains".

* The anti-Euro side would have won the referendum, and the currency would have collapsed.

* "after a deep and painful recession economic recovery began".

* "Britain would have destroyed the euro on departure, and would now be on the point of leaving the EU altogether. The idea that Farage might be the next prime minister would be quite credible."